Tester incorporating opening and closing mechanism

ABSTRACT

A tester incorporating an opening and closing mechanism includes a base ( 10 ), a cover ( 30 ) pivotably attached to the base, and a pair of master cylinders ( 40 ) pivotably attached to the base and cover. The base includes a top wall ( 12 ) and a control panel ( 18 ). Three spaced lower hooks ( 14 ) are formed on the top wall. A first sensor is mounted on one lower hook. A pair of actuators ( 16 ) is mounted behind two lower hooks. The control panel receives and sends signals. Three spaced upper hooks ( 34 ) are pivotably fixed on the cover, for engaging with the lower hooks respectively. A second sensor is mounted on the cover behind one upper hook. A third sensor ( 41   a ) is mounted on one master cylinder. The master cylinders and the actuators are controlled by the control panel, for opening and closing the cover.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to testing machines, and more particularly to testers which have a mechanism for quick and steady opening and closing thereof.

[0003] 2. Description of the Related Art

[0004] A typical tester used for testing apparatuses such as printed circuit boards comprises a cover and a base. A control panel is formed on a front wall of the base. A retaining device is formed on a top wall of the base, for retaining a printed circuit board to be tested. The cover is parallelepiped-shaped. The cover is pivotably attached to the base, for covering the base. A testing device is provided in the cover. A knob is formed on a front wall of the cover, for opening and closing the cover. When testing a printed circuit board, an operator has to lift the cover open by the knob, fix the printed circuit board on the retaining device, and close the cover to start the test. However, such manual operation is slow, laborious and inefficient. Furthermore, if the operator opens or closes the cover too quickly, the testing device in the cover is liable to sustain damage due to shock. Accuracy of the tester may then be impaired.

SUMMARY OF THE INVENTION

[0005] Accordingly, an object of the present invention is to provide a tester which has a stable automatic opening and closing mechanism.

[0006] Another object of the present invention is to provide a tester which reduces manual labor and increases efficiency.

[0007] To achieve the above objects, a tester incorporating an opening and closing mechanism in accordance with the present invention comprises a base, a cover, a pair of master cylinders and a pair of slave cylinders. The base comprises a top wall and a control panel. Three aligned and spaced lower hooks are upwardly formed on the top wall adjacent the control panel. A first sensor is mounted on a middle one of the lower hooks. The first sensor sends signals to the control panel. A pair of actuators is mounted behind the two hooks that are at opposite sides of the middle lower hook. The control panel receives and sends signals. The cover is pivotably attached to the base. Three aligned and spaced upper hooks are pivotably fixed on the cover, for engaging with the lower hooks respectively. A second sensor is mounted on the cover behind a middle one of the upper hooks. The second sensor of the cover sends signals to the control panel. Each of the master cylinders comprises a cylinder casing and a piston rod. The master cylinders are pivotably attached to the base and the cover. A third sensor is mounted on an outer surface of one master cylinder. The third sensor of the master cylinder sends signals to the control panel. The master cylinders, the slave cylinders and the actuators are controlled by the control panel, for opening and closing the cover.

[0008] Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of preferred embodiments of the present invention with the attached drawings, in which:

BRIEF DESCRIPTION OF THE DRAWING

[0009]FIG. 1 is an isometric view of a tester in accordance with a preferred embodiment of the present invention, showing the tester in a closed position; and

[0010]FIG. 2 is similar to FIG. 1, but showing the tester in an open position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Referring to FIGS. 1 and 2, a tester incorporating an opening and closing mechanism in accordance with a preferred embodiment of the present invention comprises a base 10, a cover 30, a pair of master cylinders 40 and a pair of slave cylinders 50.

[0012] The base 10 comprises a top wall 12 and a control panel 18. The control panel 18 is arranged at a front wall of the base 10, and is for receiving and sending signals. The top wall 12 is for supporting a printed circuit board (not shown) to be tested. Three aligned and spaced lower hooks 14 are upwardly formed at a front portion of the top wall 12. Each lower hook 14 is L-shaped, and comprises a vertical part and a horizontal part. A first sensor (not shown) is mounted on the vertical part and under the horizontal part of a middle one of the lower hooks 14. The first sensor sends signals to the control panel 18. A pair of actuators 16 is respectively positioned behind the two lower hooks 14 that are at opposite sides of the middle lower hook 14. Each actuator 16 comprises a slidable shaft 161 extending through a middle part thereof. A pair of holes 141 is defined in the two side lower hooks 14 respectively, corresponding to the shafts 161 of the actuators 16. The actuators 16 are controlled by the control panel 18. The actuators 16 can push the shafts 161 through the respective holes 141. A pair of pivot pedestals 121 is upwardly formed near each of opposite side edges of the top wall 12. Three aligned and spaced rear pivot pedestals 123 are upwardly formed near a rear edge of the top wall 12, and are pivotably attached to the cover 30.

[0013] The cover 30 is generally box-shaped, and is adapted to accommodate a testing device (not shown). A horizontal beam 32 is formed on a front face of the cover 30. Three spaced L-shaped blocks 321 protrude upwardly from the beam 32. A spring pin 321 a protrudes forwardly from a vertical part of each of the blocks 321. A second sensor (not shown) is mounted on a middle one of the blocks 321, and over a middle one of the spring pins 321 a. The second sensor sends signals to the control panel 18. Three spaced posts 323 depend from the beam 32. The posts 323 contact the horizontal parts respectively of the lower hooks 14, for supporting the cover 30 when the cover 30 is in a closed position. Three upper hooks 34 are pivotably attached in the beam 32, corresponding to the three lower hooks 14. Each upper hook 34 is L-shaped, and comprises a horizontal part and vertical part. The upper hooks 34 contact the spring pins 321 a respectively. A connecting bar 341 connects between the upper hooks 34 below the beam 32. A pair of pivot pedestals 36 is formed on opposite side faces of the cover 30 respectively, corresponding to the pairs of pivot pedestals 121 of the base 10.

[0014] Each master cylinder 40 comprises a cylinder casing 41 and a piston rod 43. A medium such as gas or oil is pumped into the cylinder casing 41, for pushing the piston rod 43 along the cylinder casing 41. One end of each master cylinder 40 is pivotably fixed to a corresponding pivot pedestal 36 of the cover 30, and an opposite end of each master cylinder 40 is pivotably fixed to a corresponding forward one of the pivot pedestals 121 of the base 10. The piston rods 43 are movable in the respective cylinder casings 41. A third sensor 41 a is mounted at a predetermined position on an outer surface of one of the cylinder casings 41, and a fourth sensor (not shown) is mounted on the corresponding piston rod 43. When said piston rod 43 reaches the predetermined position in said cylinder casing 41, the third sensor 41 a is activated by the fourth sensor of the piston rod 43, and the third sensor 41 a sends a signal to the control panel 18. Each slave cylinder 50 is pivotably fixed to a corresponding pivot pedestal 36, and to a corresponding rearward one of the pivot pedestals 121. Each slave cylinder 50 comprises a cylinder casing (not labeled) and a piston rod (not labeled). The slave cylinders 50 are hermetically filled with compressed gas.

[0015] Referring particularly to FIG. 1, in operation, a user at the control panel 18 starts the actuators 16. The shafts 161 of the actuators 16 are moved outwardly, and extend through the holes 141 of the side lower hooks 14. The shafts 161 push the side upper hooks 34 forwardly, and the upper hooks 34 rotate outwardly to begin disengaging from the lower hooks 14. The upper hooks 34 press the spring pins 321 a inwardly toward the blocks 321 until the upper hooks 34 disengage from the lower hooks 14. At this moment, the middle upper hook 34 contacts the second sensor of the middle block 321. The second sensor sends a signal to the control panel 18 indicating that the upper hooks 34 have disengaged from the lower hooks 14. Then the control panel 18 sends a signal to the master cylinders 40. The medium is pumped into the cylinder casings 41, and the piston rods 43 extend and push the cover 30 open. The spring pins 321 a rebound back against the upper hooks 34. When the piston rod 43 having the fourth sensor reaches said predetermined place, the third sensor 41 a of the corresponding master cylinder 40 is activated by the fourth sensor of the piston rod 43. The third sensor 41 a sends a signal to the control panel 18 indicating that the cover 30 is fully opened. The control panel 18 operates to stop pumping of the medium into the master cylinders 41, the piston rods 41 stop, and the cover 30 is maintained in the fully open position.

[0016] A printed circuit board (not shown) is placed on the top wall 12 of the base 10 for testing. Then the user at the control panel 18 sends a “close” signal to the master cylinders 40. The piston rods 43 retract back into the cylinder casings 41, and the cover 30 rotates down toward the base 10. The posts 323 contact the lower hooks 14 to support the cover 30, and the upper hooks 34 engage with the lower hooks 14. The horizontal parts of the upper hooks 34 are located under the horizontal parts of the lower hooks 14, and the middle upper hook 34 contacts the first sensor of the middle lower hook 14. The first sensor sends a signal to the control panel 18. The control panel 18 then sends a “test”signal to the testing device in the cover 30. The testing device starts testing the printed circuit board.

[0017] During opening and closing of the cover 30, the slave cylinders 50 act as springs. When the cover 30 is opened, the compressed gas in the cylinder casings of the slave cylinders 50 expands and extends the corresponding piston rods. This helps open the cover 30 quickly. When cover 30 is closed, the gas is compressed once again so as to make the cover 30 close steadily. In alternative embodiments, the second sensor of the cover 30 can be mounted on any of the blocks 321. The first sensor of the base 10 can be mounted on any of the lower hooks 14. If desired, more than one second sensor can be mounted on the cover 30, and more than one first sensor can be mounted on the base 10.

[0018] While the present invention has been illustrated by the description of preferred embodiments thereof, and while the preferred embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the present invention will readily appear to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrative examples shown and described. 

What is claimed is:
 1. A tester comprising: a base comprising a top wall and a control panel, at least one first fastener provided at the top wall adjacent the control panel, a first sensor arranged on at least one first fastener for sending signals to the control panel, and an actuator arranged adjacent at least one first fastener, the control panel being adapted to receive and send signals; a cover pivotably attached to the base, at least one second fastener provided on the cover for engaging with the at least one first fastener of the base, a second sensor arranged on the cover for sending signals to the control panel; and at least one master cylinder pivotably attached to the base and the cover respectively, a third sensor arranged on the at least one cylinder; wherein the actuator is controlled by the control panel to disengage the at least one first fastener from the at least one second fastener, and the first and second sensors are respectively activated by at least one first fastener.
 2. The tester as claimed in claim 1, wherein a plurality of spaced first fasteners are arranged on the top wall, each of the first fasteners is a first hook, and the first sensor of the base is mounted on a middle one of the first hooks.
 3. The tester as claimed in claim 2, wherein a hole is defined in each of side first hooks located at opposite sides of the middle first hook, a pair of actuators is arranged behind the side first hooks, and each of the actuators comprises a slidable shaft extending through a corresponding hole.
 4. The tester as claimed in claim 2, wherein a beam is arranged at a front of the cover, a plurality of spaced posts depends from the beam, and the posts are supported on the first hooks respectively when the cover is in a closed position.
 5. The tester as claimed in claim 4, wherein a plurality of second fasteners is provided on the cover, each of the second fasteners is a second hook, and the second hooks are pivotably attached to the beam for engaging with the first hooks respectively.
 6. The tester as claimed in claim 5, wherein a bar connects between the second hooks.
 7. The tester as claimed in claim 6, wherein a plurality of blocks is upwardly arranged on the beam corresponding to the second hooks, the blocks are positioned behind the second hooks respectively, the second sensor of the cover is arranged on a middle one of the blocks, and a plurality of spring pins is connected between the blocks and the second hooks respectively.
 8. The tester as claimed in claim 1, wherein the tester comprises a pair of master cylinders, each of the master cylinders is attached to lateral sides of the tester respectively, each of the master cylinders comprises a cylinder casing and a piston rod, and the third sensor is mounted on an outer surface of one of the cylinder casings.
 9. The tester as claimed in claim 1, further comprising a pair of slave cylinders.
 10. A tester for testing a circuit board, comprising: a base comprising a top wall adapted for supporting the circuit board thereon and a control panel, a plurality of spaced first hooks provided on the top wall, a first sensor arranged on one of the first hooks for sending signals to the control panel, at least one actuator arranged adjacent the first hooks, the control panel being adapted to receive and send signals; a cover pivotably attached to the base, a plurality of second hooks being provided on the cover and engaging with the first hooks of the base respectively, a second sensor being arranged on the cover for sending signals to the control panel; and a pair of cylinders pivotably attached to the base and the cover respectively, a third sensor being arranged on one of the cylinders; wherein in operation the control panel activates the at least one actuator to disengage the first hooks from the second hooks, the second sensor sends a signal to the control panel indicating that the second hooks are disengaging from the first hooks, the cylinders are activated to open the cover, the third sensor sends a signal to the control panel when the cover is fully opened; and in reverse operation, the control panel activates the cylinders to close the cover, the first hooks engage with the second hooks, and the first sensor sends a signal to the control panel indicating that the cover is closed.
 11. The tester as claimed in claim 10, wherein each of the first hooks comprises a vertical part and a horizontal part, and the first sensor of the base is arranged on the vertical part of a middle one of the first hooks.
 12. The tester as claimed in claim 11, wherein a hole is defined in each of the first hooks, and the at least one actuator comprises a slidable shaft that extends through the hole of one respective first hook.
 13. The tester as claimed in claim 10, wherein a beam is arranged at a front of the cover, a plurality of spaced posts depends from the beam, and the posts are supported on the first hooks respectively.
 14. The tester as claimed in claim 13, wherein a plurality of blocks is upwardly arranged on the beam corresponding to the second hooks, the blocks are positioned behind the second hooks respectively, the second sensor of the cover is arranged on one of the blocks, and a spring pin protrudes forwardly from each of the blocks.
 15. The tester as claimed in claim 10, wherein a pivot pedestal is provided at each of lateral sides of the cover, a pivot pedestal is provided at each of lateral sides of the base, and each of the cylinders is attached to a respective pivot pedestal of the cover and of the base.
 16. A tester comprising: a base and a cover pivotally attached to each other around rear portions thereof; a fastener pivotally mounted on a front portion of one of said base and said cover; a hook formed on another front portion of the other of said base and said cover and preventing the fastener from leaving the hook in a vertical direction; a first actuation means for generating a pivotal movement of the fastener around said front portion for disengagement between the fastener and the hook; and a second actuation means for generating a pivotal movement of the cover relative to the base about said rear portions for opening the cover, after a sensor, which is located around said front portion and opposite to said hook, has been actuated by said fastener to show complete disengagement between the hook and the fastener. 